In a client-server architecture, a client system, such as a computer, may call an application, such as a program, a service, or a web service, at a server to interact with the application through the Internet or an intranet. A service, such as a web service, is an application (or program) that may make itself available over the Internet or an intranet, may use standardized messaging, such as XML (eXtensible Markup Language) and Simple Object Access Protocol (SOAP), and may use some type of location mechanism, such as UDDI (Universal Description, Discovery, and Integration), to locate the service and its public Application Program Interface (API).
To call a service through the Internet or intranet, the client system makes a call (e.g., using messages) through an API, which defines the way the client communicates with the service. The service instantiates objects, such as business objects, in response to the API call. The term “object” refers to a data structure including at least one of data and related methods, while the phrase “business object” refers to an object used in connection with a business process or a task.
An example of a service is a “flight reservation” service, which may be called through a network (e.g., the Internet and/or the intranet) by a client system. The flight reservation service may allow a user at a client system to perform a variety of flight reservation tasks, such as display, save (i.e., make), and edit (i.e., modify) reservations. The data and method associated with the service may be structured and instantiated as one or more objects, such as business objects.